Turns out that those barrels you saw on the tour of your local winery may have only been for show. Wooden barrels are now being replaced with steel vats, but to keep the wine's expensive oaken taste, it gets mixed with "barrel alternatives." That's a fancy term for wood staves, chips, and even shavings thrown into a vat along with the wine. Why? Because using shavings shaves a dollar off the price of a bottle (on their end, of course, not ours), up until all those splinter-related lawsuits presumably start pouring in.
But that's not the only way wineries are cutting corners. A lot of wine is made using something called "Mega Purple," which sounds like the main villain in a coloring-themed manga. It's a grape concentrate, or slurry, which big wine labels add to underwhelming red wine to intensify the flavor and color and sometimes even to mask spoilage. It's estimated that over 25 million bottles get spiked with Mega Purple on a yearly basis. Many wineries rely so heavily on it that they have their own reverse-osmosis machines which let them make their own concentrates by extracting the alcohol from their shitty wines to pump up slightly less shitty wine. Yummy.